<h2>Why is this an issue?</h2>
<p>When explicitly setting the region on an AWS Client, you should always prefer providing the value from the Enum <a
href="https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/index.html?com/amazonaws/regions/Regions.html">Regions</a> instead of a hardcoded String.
This will allow you to transparently support any change in the API and avoid mistakes.</p>
<p>This rule reports an issue when a hardcoded string is used instead of an available enum value.</p>
<h3>Noncompliant code example</h3>
<pre>
AmazonS3ClientBuilder.standard().withRegion("eu_west_1").build();
</pre>
<h3>Compliant solution</h3>
<pre>
AmazonS3ClientBuilder.standard().withRegion(Regions.EU_WEST_1).build();
</pre>

